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Query: UMLS:C0013080 (Down syndrome)
 14,180 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Content of phenylalanine and tyrosine was increased in blood serum in mongolism. When 4 patients with mongolism and 10 healthy persons were loaded with 1-phenylalanine, content of the amino acid in blood serum of patients exceeded 1.5--2-fold that found in healthy persons within 4 and 6 hrs after the treatment. The hydroxylation rate of phenylalanine was lower in mongolism as compared to normal state; it corresponded to the rate of phenylalanine hydroxylation in atypical homo- and heterozygote patients bearing "phenylketonuria" gene and in patients with viral hepatitis. Concentration of tyrosine was distinctly higher in the impaired patients within 2--6 hrs after the loading as compared with the healthy persons. But content of tyrosine was increased only slightly in patients with mongolism during the loading and excretion of homogentisinic acid with urine was decreased. These data suggest that activity of phenylalanine hydroxylase system is impaired in liver tissue in mongolism. Excretion of phenylpyruvic acid with urine was not observed in the patients and healthy persons both before and during the amino acid loading. The data obtained suggest that impairment of phenylalanine and tyrosine turnover in mongolism appears to be one of the factors responsible for disturbance of neurotransmitter synthesis and to be related to development of mental retardation.
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PMID:[Disorders of phenylalanine and tyrosine metabolism in Down's syndrome]. 15 71

An analytical description is presented of 942 mentally retarded persons from the county of West Zealand. The prevalence of mental retardation (i.e. persons who were registered with an IQ below 75) was 0.36%. Almost half of the patients were living in institutions. Of the patients 43% were women and 57% men. Important aetiological factors are listed. In almost one third of the patients, similar cases were present among the closest relatives; 30% of the patients were born as the fourth or subsequent child in the family; one sixth of the mothers were more than 35 years old at the birth of the handicapped child. Twenty-two percent of the patients with IQs below 50 had Down's syndrome. Seventeen percent of the patients had epilepsy had 11% cerebral palsy. In the central institution all patients had psychiatric or somatic complications.
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PMID:Disease pattern among 942 mentally retarded persons in a Danish county. 15 88

There is increasing recognition that autism is a syndrome, not a disease entity. But it is not yet clear why some children develop autistic behavior more easily than others. It has been noted that autistic symptoms occur more frequently in children with mental retardation, blindness, congenital rubella, phenylketonuria, etc., and that there are very few cases of classical infantile autism in the general population. Very rarely has autism been associated with Down's syndrome. This is a report of a case of Down's syndrome and infantile autism.
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PMID:A case of infantile autism associated with Down's syndrome. 15 85

Chromosome imbalance (aneusomy) is the leading known cause of both spontaneous abortion and mental retardation in human beings. The primary abnormality is thought to result from quantitative changes of transcription products from the unbalanced genetic material. To document this point, I compared chromosome 21-specific transcription in skin fibroblasts from subjects with monosomy 21, disomy 21 (normal), and trisomy 21 (Down syndrome). Polyadenylylated RNA [poly(A)-RNA], which is enriched in messenger and messenger-precursor RNA sequences, was isolated from the above fibroblast lines. Radioactive DNA (cDNA) complementary to these RNAs was synthesized with reverse transcriptase (RNA-dependent DNA polymerase). These cDNAs were hybridized with (i) DNA from a cell line with a mouse genome plus human chromosome 21 and (ii) mouse DNA. Subtraction of the amount of hybridization in experiment ii from that in experiment i yielded a measure of human chromosome 21-specific RNA sequences. The results were consistent with gene dosage at the transcriptional level; for monosomy 21-derived cDNA, 0.6% (of the total cDNA) hybridized specifically to human chromosome 21; for disomy 21-derived cDNA, 2% hybridized; and for trisomy 21-derived cDNA, 3% hybridized. Thus, for DNA sequences on chromosome 21 in human skin fibroblasts, transcription depends on DNA dosage. Characterization of the chromosome 21-specific RNA sequences quantitated in these experiments could help to elucidate the mechanisms by which abnormal karyotypes result in abnormal phenotypes.
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PMID:Down syndrome: gene dosage at the transcriptional level in skin fibroblasts. 15 66

A total of 600 handicapped patients had dental rehabilitation under general anesthesia during an eight-year period. Handicaps included mental retardation, cerebral palsy, Down syndrome, seizure disorders, autism, cystic fibrosis, osteogenesis imperfecta, and muscular dystrophy. No significant complications developed in the majority of patients. This is attributed to thorough preoperative evaluation, appropriate anesthetic management, and vigilant postoperative observation.
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PMID:Complications related to the administration of general anesthesia in 600 developmentally disabled dental patients. 15 47

Pseudocholinesterase activity and the phenotypes controlled by the E1 locus have been determined in a sample of 307 Down's syndrome patients and 206 patients suffering from nonspecific mental retardation and compared to those in the healthy population. Both groups of patients have an elevated frequency of phenotypes possessing the rate E1f allele. The mentally retarded patients have a higher mean pseudocholinesterase activity than those with Down's syndrome who, in turn, have activity than the healthy controls.
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PMID:Pseudocholinesterase activity and E1 phenotypes in Down's syndrome and mental retardation. 15 60

Since mongoloids have been reported to differ from other patients with mental retardation by being virtually free of atheromatosis, we analysed plasma lipids and lipoproteins in twenty mongoloid and in twenty age-matched non-mongoloid mentally retarded patients living in the same institution. Plasma total cholesterol in the mongoloids did not differ significantly from that of the control group, but it was low in both groups in comparison with the Finnish population in general. Plasma total triglyceride concentration was higher (P less than 0.01) in the mongoloids than in the controls. This was reflected in higher VLDL-triglyceride and-cholesterol concentrations in the mongoloids. Plasma apolipoprotein B levels were higher (P less than 0.05) and the ratio of apolipoprotein A-1 to apolipoprotein B was lower (less than 0.05) in the mongoloids. The plasma lipid concentrations were in accordance with the significantly higher relative body weights in the mongoloid group. Blood pressure was slightly but significantly lower and cigarette smoking was less common in patients with Down's syndrome. Our results did not explain the reported lower frequency of atheromatosis in Down's syndrome.
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PMID:Plasma lipids and lipoproteins in Down's syndrome. 16 Jun 10

Neutralization tests for poliovirus antibodies were carried out on 74 patients in an adult mental deficiency hospital: 37 patients with Down's syndrome and 37 non-Down's mental defectives. The distribution of antibody titres to poliovirus types 1, 2 and 3 did not differ significantly between the two groups. Most patients had antibody to at least one poliovirus type but less than a third had antibodies at a titre of 1/8 or greater to all three types. The low level of poliovirus immunity in this population may be of epidemiological importance.
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PMID:Serum antibody to poliovirus in patients in a mental deficiency hospital, with particular reference to Down's syndrome. 21 Nov 62

The prevalence of antibody to hepatitis A virus (anti-HAV) was determined in 854 people living in a large institution for the mentally retarded in Melbourne. Altogether 638 (74.4%) of the subjects were found to have specific antibody detectable by solid-phase radioimmunoassay (SPRIA). No difference in antibody prevalence was observed between males and females; however, the prevalence was higher among subjects with Down syndrome (84.1%) than those of other forms of mental retardation (72.8%). In both groups there was an increase in prevalence of antibody with increasing age and duration of institutionalization. When compared with the open community, patients in this institution have a higher prevalence of antibody and appear to acquire their infections at an earlier age.
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PMID:Prevalence of antibody to the hepatitis A virus in a large institution for the mentally retarded. 21 14

Visualization of the neuron in its entirety through the use of the rapid Golgi method has permitted detection of several pathobiological features of neurons that are intimately associated with profound mental retardation in infants and children. In cases of unclassified mental retardation, dendrites and particularly dendritic spines exhibit severe developmental abnormalities. Dendritic spines, the postsynaptic components of axospinodendritic synapses, may be absent or abnormally long and thin in retardates. Evidence is presented that some cases of progressive neurobehavioral deterioration in infancy and early childhood may be due to progressive degeneration of dendritic spine systems (dendritic spine "dysgenesis"). Golgi and electron microscopic studies of neurons in human and feline ganglioside storage diseases indicate that ganglioside accumulation in cortical neurons initiates several complex alterations in neuronal geometry and morphology. Small and medium pyramidal cells form massive structural compartments (meganeurites) that frequently give rise to secondary neurites and other embryonic growth processes. Meganeurites may possess spines and spine-synapses. Other cells such as large pyramidal neurons may exhibit many somatic spines, whereas intrinsic cells of the cortex (and caudate) are unaffected morphologically by ganglioside accumulation. It is suggested that neuronal geometry distortion and aberrant synaptogenesis are important factors in the onset of neuronal dysfunction in ganglioside storage disorders. These studies also point to an important role of gangliosides in neurite formation in immature mammalian cortical neurons. Perisomatic processes and somatic spines are normal morphological components of the cell body of Purkinje cells through the 28th fetal week of human gestation. By 36 weeks the Purkinje cell somas exhibit a smooth surface contour. Prominent polydendritic processes, perisomatic protuberances, and somatic spines are detectable by Golgi methods applied to Purkinje cells in Menkes' disease and Down's syndrome long after these somatic components should normally disappear. Thus Purkinje cell soma membrane differentiation is a particularly sensitive process that can provide information on mechanisms of site-specific membrane regulation.
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PMID:Pathobiology of cortical neurons in metabolic and unclassified amentias. 21 50


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